title: Brain diffusion-weighted imaging in Friedreich's ataxia.
abstract: BACKGROUND
  Friedreich ataxia (FRDA) is the commonest form of autosomal recessive ataxia. This study aimed to define the extent of the brain damage in FRDA patients and to identify in vivo markers of neurodegeneration, using diffusion-weighted imaging (DWI).
  
  
  METHODS
  We studied 27 FRDA patients and 21 healthy volunteers using a 1.5 T scanner. Axial DW images were obtained and mean diffusivity (MD) maps were generated. Region of interests (ROIs) included medulla, pons, inferior, middle and superior cerebellar peduncles (ICP, SCP, MCP), dentate nucleus, cerebellar white matter, thalamus, caudate, putamen, pallidus, pyramidal tracts at level of posterior limb of internal capsule (PLIC), optic radiations (OR), and corpus callosum. Histograms of MD were generated for all pixels in the whole cerebral hemispheres and infratentorial compartment. Disease severity was assessed by the International Cooperative Ataxia Rating Scale (ICARS).
  
  
  RESULTS
  FRDA patients had significantly higher MD values than controls in medulla (P < 0.001), ICP (P < 0.001), MCP (P < 0.01), SCP (P < 0.001), OR (P < 0.001), and at the level of the infratentorial structures such as brainstem (P < 0.01), cerebellar hemispheres (P < 0.01), and especially in the cerebellar vermis (P < 0.001). MD values were strongly correlated with disease duration and ICARS score.
  
  
  CONCLUSIONS
  Our results showed that DWI is a suitable non-invasive technique to quantify the extent of neurodegeneration in FRDA, that appears more extended than previously reported, showing a microstructural involvement of structures such as OR and MCP.
authors.affiliation: MR Spectroscopy Unit, Department of Internal Medicine, Aging and Nephrology, University of Bologna, Bologna, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Rizzo
authors.forename: Caterina
authors.initials: C
authors.lastname: Tonon
authors.forename: Maria Lucia
authors.initials: ML
authors.lastname: Valentino
authors.forename: David
authors.initials: D
authors.lastname: Manners
authors.forename: Filippo
authors.initials: F
authors.lastname: Fortuna
authors.forename: Cinzia
authors.initials: C
authors.lastname: Gellera
authors.forename: Antonella
authors.initials: A
authors.lastname: Pini
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ghezzo
authors.forename: Agostino
authors.initials: A
authors.lastname: Baruzzi
authors.forename: Claudia
authors.initials: C
authors.lastname: Testa
authors.forename: Emil
authors.initials: E
authors.lastname: Malucelli
authors.forename: Bruno
authors.initials: B
authors.lastname: Barbiroli
authors.forename: Valerio
authors.initials: V
authors.lastname: Carelli
authors.forename: Raffaele
authors.initials: R
authors.lastname: Lodi
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004185:Disability Evaluation; D005260:Female; D005621:Friedreich Ataxia / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D012044:Regression Analysis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D055815:Young Adult